public class csmz2333 {
    public  static  void main(String[] args){
        int i=20;
        long l=i;
        float f=l;
        double d =f;
        System.out.println("long类型变量l:"+l);
        System.out.println("float类型变量f:"+f);
        System.out.println("double类型变量d:"+d);
    }
}